fix: 补建跨实例同步缺失的 synced_pack_catalog / synced_pack_instances 表

移植跨实例同步时遗漏了这两张表，导致 20261003000200_synced-pack-selection.sql 对不存在的 synced_pack_catalog 执行 ALTER 而迁移失败、启动器无法初始化。新增 20261003000050_synced-pack-tables.sql（顺序位于 feature-tables 之后、pack-selection 之前）补建。

packages/app-lib/migrations/20261003000050_synced-pack-tables.sql

@@ -0,0 +1,32 @@
+-- Synced pack catalog tables.
+--
+-- These two tables were missed when the sync feature tables were ported;
+-- 20261003000200_synced-pack-selection.sql alters `synced_pack_catalog`,
+-- so it must exist first.
+
+CREATE TABLE synced_pack_catalog (
+	id TEXT PRIMARY KEY NOT NULL,
+	project_type TEXT NOT NULL CHECK (project_type IN ('resourcepack', 'datapack')),
+	file_name TEXT NOT NULL,
+	sha1 TEXT NOT NULL UNIQUE,
+	size INTEGER NOT NULL CHECK (size >= 0),
+	game_versions_json TEXT NOT NULL DEFAULT '[]',
+	enabled INTEGER NOT NULL DEFAULT 1 CHECK (enabled IN (0, 1)),
+	created_at INTEGER NOT NULL,
+	modified_at INTEGER NOT NULL
+);
+
+CREATE INDEX synced_pack_catalog_type ON synced_pack_catalog(project_type, modified_at);
+
+CREATE TABLE synced_pack_instances (
+	pack_id TEXT NOT NULL,
+	instance_id TEXT NOT NULL,
+	excluded INTEGER NOT NULL DEFAULT 0 CHECK (excluded IN (0, 1)),
+	materialized_path TEXT,
+	modified_at INTEGER NOT NULL,
+	PRIMARY KEY (pack_id, instance_id),
+	FOREIGN KEY (pack_id) REFERENCES synced_pack_catalog(id) ON DELETE CASCADE,
+	FOREIGN KEY (instance_id) REFERENCES instances(id) ON DELETE CASCADE
+);
+
+CREATE INDEX synced_pack_instances_instance ON synced_pack_instances(instance_id, excluded);